1. Field of the Invention
This invention relates to the field of mass storage systems. In particular, the invention relates to the management of storage transactions in, and the configuration of, intelligent storage area networks.
2. Description of the Related Art
The storage of large amounts of data in so-called mass storage systems is becoming a common practice. Mass storage systems typically include storage devices coupled to file servers on data networks. Users in the network communicate with the file servers for access to the data. The file servers are typically to specific storage devices connected via data channels. The data channels are usually implemented with point-to-point communication protocols designed for managing storage transactions.
As the amount of storage increases, and the number of file servers in communication networks grows, the concept of a storage area network (SAN) has arisen. Storage area networks connect a number of mass storage systems in a communication network which is optimized for storage transactions. For example, fiber channel arbitrated loop FC-AL networks are being implemented as SANs. The SANs support many point-to-point communication sessions between users of the storage systems and the specific storage systems on the SAN.
File servers and other users of the storage systems are configured to communicate with specific storage media. As the storage systems expand or media is replaced in the system, re-configuration is required at the file servers and other users. Also, if a need arises to move the data from one device to another, in a so-called data migration operation, it is often necessary to block access to the data during the migration process. After migration is complete, re-configuration at the user system must be executed to make the data available from the new device.
Overall, as the complexity and size of storage systems and networks increase, the problems of managing configuration of the users of the data and of the storage systems themselves multiply. Accordingly, there is a need for systems that simplify management of storage systems, while taking advantage of the flexibility and power of the SAN architecture.
The present invention provides an user interface for use in configuring a storage server for management of storage resources coupled to the storage server. In a preferred system the graphical user interface supports tools for establishing virtual devices and virtual circuits for storing data.
The storage server according to the present invention includes a plurality of communication interfaces. A first set of communication interfaces in the plurality is adapted for connection to all kinds of users of data. A second set of communication interfaces in the plurality is adapted for connection to respective devices in a pool of storage devices. The user interface provides tools for configuring data processing resources in the server coupled to the plurality of communication interfaces for transferring data among the interfaces. The data processing resources comprise a plurality of driver modules and configurable logic linking driver modules into data paths. Each configured data path acts as a virtual circuit that includes a set of driver modules selected from the plurality of driver modules. A data storage transaction which is received at a communication interface is mapped to one of the configured data paths according to the initiating host and according to the logical address of the storage extent subject of the transaction.
The user interface includes tools to configure virtual devices and virtual circuits, having a logical address such as a LUN number and target device identifier, to a set of physical storage devices coupled to communication interfaces in the storage server, and a set of client hosts coupled to communication interfaces in the storage server.
The user interface provides tool for configuration of the storage system. It comprises a display and a user input device, such as a mouse, touch screen or other pointing device. Data processing structures are coupled with the display and the user input device, which include logic to manage images displayed on the display, either simultaneously in groups, in a logical sequence, or in an interactive sequence. The images include first image arranged to prompt the user to input data concerning host systems coupled to the server, the second image arranged to prompt the user to input data concerning storage resources including virtual devices and physical storage devices accessible using the server, and a third image arranged to prompt a user to input data concerning logical addresses used by the host systems access the storage resources. Also, a communication interface is included that is arranged to provide the input data to the server.
For a storage system supporting a plurality of host systems, the first image includes a graphic tool allowing a user to add a host to the plurality of host systems. Also, the first image may comprise the display construct, such as a table listing host systems available for configuration. The preferred embodiment, the table includes for each entry a host name field, a port number field for an identifier of the port in the server, and a protocol ID field for an identifier of the host for used by a storage channel protocol. Other fields can be included, such as a description field for a description of an associated host, and a unique identifier field, such as the field for a World Wide Name.
For storage systems supporting storage resources including a plurality of storage elements, the second image includes a graphic tool allowing a user to add a storage elements to the plurality of storage elements. For example, the preferred embodiment the second image comprises a display construct such as icons arranged in a hierarchical tree, that indicate storage elements available for configuration.
In one embodiment, the display construct used for representing storage elements comprises a hierarchical tree, and the storage elements available for configuration include a mirror storage element as a head of the tree, and two or more storage elements configured as parts of the mirror storage element as branches of the tree. Likewise, storage elements available for configuration include a stripe storage element in some embodiments, as a head of the tree, and two or more storage elements configured as parts of the stripe storage element as branches of the tree. In other embodiments, storage elements available for configuration include a logical unit as head of the tree, and a plurality of logical partitions of the logical unit as branches of tree.
In yet another embodiment, the third image comprises a display construct listing logical addresses of the configured storage resources. Logic addresses comprise for example a Logical Unit Number LUN. In another embodiment, the logical address comprises a World Wide Name of a host system mapped to particular storage resources.
The communication interface for the user interface in various embodiments comprises a network interface for communication with a server being configured across the network like Ethernet, a serial port for communication with a remote server, and an interior bus interface for an integral display system on the server being configured.
According to another aspect of the invention, the plurality of driver modules includes a protocol server for a protocol supported on a communication interface in the plurality of communication interfaces. The protocol server recognizes target identifiers which identify particular storage extents according to the protocol on the interface. Transactions addressed to the particular storage extent are mapped to a particular configured data path in the server.
The data paths configured in this manner act as virtual storage devices. Users of the data communicate with a communication interface on the storage server according to a protocol for a particular storage device. Inside the server, the transactions according to that protocol are mapped to a virtual storage device implemented by sets of drivers. Setting up and changing the storage tasks performed in a particular data path, and setting up and changing the mapping of a storage extent from one data path to another are accomplished by configuring the sets of driver modules within the storage server.
The communication protocols supported on the interfaces adapted for communication with users of the data and storage elements in various embodiments include fiber channel FC protocols such as the Fiber Channel Arbitrated Loop (FC-AL), and the Fiber Channelxe2x80x94Small Computer System Interface (SCSI) based protocol known as FCP. Other protocols include such protocols as the Internet Protocol (IP), the High Performance Parallel Interface (HIPPI), the Intelligent Peripheral Interface (IPI) and other protocols combined with or in place of these examples. According to each of these protocols, storage transactions can be executed which identify particular target storage extents, such as using the SCSI target ID and a Logical Unit Number (LUN). Thus, in this example, a storage transaction which identifies a SCSI target ID and a LUN, can be mapped in response to the target ID and the LUN to a particular virtual circuit in the storage server.
The present invention provides an intelligent storage routing device which manages logical and physical access to a pool of shared storage devices. The device is logically closer to the client server than to the storage devices, and responds to client specific requests for storage transactions which require accessing and sharing a storage area network coupled to the device. The device manages the use of a cache memory to enhance performance. Key functions provided at the device include authentication and access permission logic, virtual circuit mapping, storage mirror functions, and a large non-volatile cache. With these basic functions, many powerful storage management applications can be implemented with existing servers and storage devices, which facilitates the addition of new storage to networks.
Other aspects and advantages of the present invention can be seen on review of the figures, the detailed description and the claims which follow.